It has long been known that it would be desirable to utilize sugars contained in cellulose and hemicellulose of lignocellulosic residues for the production of fuels and value-added chemicals in bio-refinery arrangements. Lignocellulosic residues include such materials as corn stover that consists of a heterogeneous three-dimensional matrix comprised primarily of cellulose, hemicellulose and lignin. It has long been known that because of the heterogeneous nature of lignocellulose, the cellulose and hemicellulose are not directly accessible to relatively large molecules such as cellulase enzymes.
Heretofore, acid pretreatment processes have been developed to hydrolyze and remove hemicellulose, and thereby increase the susceptibility of the cellulose in the matrix to cellulolytic attack by cellulase enzymes. While this approach has worked with some degree of success, it is long been known that these acid pretreatment processes have high capital and operating costs due to high temperatures and pressures required, and further produce significant amounts of toxic decomposition products depending upon the pretreatment severity provided by the process. Another shortcoming attendant with this same approach is that these same thermal decomposition products represent a loss of potential sugars that could be utilized for subsequent fermentations.
Therefore, a method for treating a biomass, and an enzyme that when utilized with a treatment process that would reduce the severity of acid pretreatments, lower the energy and capital costs to allow increased yields of hemicellulose-derived sugars and minimize the formation of toxic by-products, is the subject matter of the present application.